A car first registered in Great Britain needs its first MOT on the third anniversary of the date it was registered. In Northern Ireland the first test comes at four years, not three — a separate regime, run by the Driver and Vehicle Agency rather than DVSA. The test costs at most £54.85 in Great Britain and a set £38.00 in Northern Ireland, and that fee buys the inspection only, not the work it finds. A car can also pass with faults written on the certificate: since 20 May 2018 defects have been graded Minor, Major or Dangerous, and only Major and Dangerous fail. What to check before it goes in is the wear three years produces — tyres, brake discs and bulbs — because DVSA publishes no failure rate by vehicle age, so no honest figure exists for a three-year-old car on its own.
Working out the date
The three years run from first registration — not from the day the car was built, and not from the day you bought it. That distinction does most of the work here.
If you are buying something nearly new, the car may have been registered well before it reached the forecourt. Pre-registered stock, ex-demonstrators and cars that came back early off a finance agreement all carry a registration date that can sit months, sometimes more than a year, ahead of where the mileage and the condition suggest. The first MOT follows the registration date regardless. That date is printed on the V5C, and it is the only one worth working from.
Our MOT check tool turns a first-registration date into the date the first test falls due. Its dates are the Great Britain ones, so a Northern Ireland car gets a year longer than the tool shows. For a car that has already been tested, the official record is at gov.uk/check-mot-history.
What the grades mean, and why a Minor still passes
This is the single most misunderstood part of the test. The change on 20 May 2018 replaced a plain pass-or-fail with a graded result, and a lot of people still read any comment on the certificate as bad news.
| Grade | Effect on the result | What it means |
|---|---|---|
| Dangerous | Fails the test | A direct and immediate risk to road safety, or a serious environmental impact. The car should not be driven away. |
| Major | Fails the test | A fault that may affect safety or the environment. It has to be repaired and the car retested. |
| Minor | Does not fail the test | A fault with no significant effect on safety. Recorded on the certificate; repair it as soon as you can. |
| Advisory | Does not fail the test | Not a defect at all — a note that an item is wearing but is still inside its limit. |
So a certificate can say Pass and still list several items underneath. Note which way round that works, though. A Minor or an advisory never causes a failure, but neither one implies a pass either: a car can be refused a certificate for a Major defect and still carry advisories about other items on the same result. Our answer page on what an MOT advisory means goes through how to read one, and whether it fails next year.
What actually fails cars, and how much of it applies here
DVSA publishes the results of the whole Great Britain programme. Across classes 3 and 4 in 2025/26 the initial failure rate was 27.51%. Lamps, reflectors and electrical equipment is the most common defect category, recorded in 10.44% of all tests. Tyres appear in only 6.23% of tests but account for 60.60% of every defect graded Dangerous — the one place where how often a fault turns up and how serious it is point in opposite directions.
Read all of that as a Great Britain-wide category rate across every car tested, of every age — not as odds for the car in front of you. DVSA’s tables do not separate a three-year-old hatchback from a fifteen-year-old one, and we are not going to invent a first-test-only failure rate that nobody publishes. The full category tables, both columns and the inversion between frequency and severity, are set out in our guide to the DVSA MOT failure data, and why cars fail the MOT ranks the categories in short form.
What that points to on a three-year-old car
Here the published data stops and reasoning starts, and it is worth saying which is which. What follows is inference about how components wear, not a statistic.
A three-year-old car is usually still on its original tyres. The DfT National Travel Survey put average annual car mileage in England at 7,100 miles in 2024 — a figure respondents estimate themselves rather than one read off odometers. Three years of that is roughly 21,300 miles. Whether an original set survives 21,300 miles depends on the car, the driving and whether the fronts were ever swapped to the rear. It is the first thing to put a depth gauge on rather than assume.
Brakes are the second thing. Pads and discs wear with miles, but discs also corrode with time and short journeys, so a low-mileage three-year-old car that has done a lot of cold two-mile trips is a more plausible brake candidate than a high-mileage motorway car. Low mileage is not the same as low wear.
Bulbs are the third, and the cheapest. Lamps and electrical equipment is the most frequent category on the whole list, and a dead number plate lamp or a failed brake light is something you can find yourself in two minutes with a friend on the pedal.
What we would not expect at three years is the slow stuff: structural corrosion, perished bushes, tired dampers. Wear of that kind takes years and miles to arrive. That is reasoning about components, though, not a DVSA breakdown by vehicle age — there isn’t one in the published tables.
What the test costs
| Test | Great Britain (DVSA) | Northern Ireland (DVA) |
|---|---|---|
| Car (class 4) | £54.85 maximum | £38.00 set price |
| Retest | No separate published figure — GOV.UK sets out when a partial retest is free | £29.50 set price |
The two are not the same kind of number. The Great Britain figure is a maximum set by DVSA and charged by private garages, which are free to charge less, and many do to win the servicing work. Northern Ireland’s are set prices charged at DVA’s own test centres, where there is nothing to shop around for. Either way the fee buys the inspection and nothing else: a car that needs two tyres at its first test will spend more on the tyres than on the test.
What a used buyer should actually do
The standard advice is to read the MOT history before buying, and it is good advice. At the first test it does not apply, because there is no history yet. A car sold at two and a half years old has an empty record. The tool that protects you on a ten-year-old car tells you nothing at all here.
So the order changes:
- Work from the V5C registration date, not the plate age identifier and not the advert. That date sets the first test.
- Ask whether the first MOT has been done. If it has, ask to see the certificate — and read the advisories on it, because they sit on a pass and are easy to skip past.
- Check all four tyres yourself, including the inner shoulders, where uneven wear hides out of sight from the kerb.
- Do not read low mileage as low wear. Corroded discs and perished rubber are age faults, not mileage faults.
Once a car does have a history — from its second test onwards — the thing to look for is repetition. A repeat advisory in the same category two tests running is a cost that has not been spent yet. Someone has to spend it, and if you buy the car, that someone is you. Public MOT history goes back to 2005 in Great Britain but only to 2017 in Northern Ireland, so an older Northern Ireland car carries a shorter paper trail through no fault of its own.
If the car is in Northern Ireland, buying a car in Northern Ireland covers the rest of the differences. Is my car exempt from an MOT deals with the ages and vehicle types that never need one, and our MOT guide covers the test itself once a car is past its first.
The short version
- First MOT: the third anniversary of registration in Great Britain, four years in Northern Ireland.
- Minor defects do not fail the test. Advisories are not defects. Only Major and Dangerous fail.
- DVSA 2025/26, classes 3 and 4: a 27.51% initial failure rate — a Great Britain-wide rate across cars of every age, not this car’s odds. Nobody publishes a figure for three-year-olds on their own.
- Tyres are 6.23% of tests but 60.60% of every defect graded Dangerous. Check all four first.
- £54.85 maximum in Great Britain, £38.00 in Northern Ireland — the test only, never the repairs.
- A car at its first test has no MOT history to read, so check the registration date and the consumables instead.
You can filter by year and mileage in our used car search.
